Protesters are attempting to block astronomers from building the Thirty Meter Telescope atop Mauna Kea on the Big Island of Hawaii.

TMT Collaboration

Hawaii’s Supreme Court began hearing oral arguments today over the fate of the Thirty Meter Telescope, which could one day become the world’s largest. The Associated Press has put together a nice summary of the recent legal battle here.

Some locals say the land coveted by astronomers atop Mauna Kea on the Big Island is sacred to their culture, and point to the 13 telescopes already built as evidence no more are needed.

Astronomers counter that the site has some of the best skies in the Northern Hemisphere, and the TMT collaboration spent seven years gaining approval.

Protesters halted construction in April. And in June activists heaved boulders onto the Mauna Kea Observatory Road to thwart the restart of building. That prompted officials to close the road to the public entirely, including tourists and amateur astronomers.

The closure was lifted in early August after law enforcement arrested seven protesters at the summit. The same night, 20 more were arrested on nearby Maui, as they halted construction on the unrelated 4-meter Daniel K. Inouye Solar Telescope, soon to be the largest of its kind.

However, a new emergency rule remains in effect. In July, Hawaiian officials restricted nighttime visitors to only certain parts of the mountain. The change was designed to stop protestors, but night-sky photographers and amateur astronomers say it makes some of their activities illegal too.

Eric Betz is an associate editor of Astronomy. He's on Twitter: @ericbetz.